• International Journal of Vascular Biomedical Engineering
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• v.1 no.2
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• pp.13-19
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• 2003

Endothelial release of nitric oxide (NO) contributes to the regulation of vascular tone by inducing vascular relaxation. To estimate the blood flow-dependent nitric oxide level and half-life (T1/2) of nitric oxide in vivo state, we investigated the change of aortic NO currents during the change of aortic blood flow rate using NO-selective electrode system and electromagnetic flowmeter in the aorta of anesthetized rats. Resting mean aortic blood flow rate was $49.6{\pm}5.6ml/min$ in the anesthetized rats. NO currents in the aorta were increased by the elevation of blood pressure and/or blood flow rate. When the aortic blood flow was occluded by the clamping, aortic NO currents were decreased. The difference of NO concentration between resting state and occluded state was $1.34{\pm}0.26{\mu}M$ (n=7). This NO concentration was estimated as blood flow-dependent nitric oxide concentration in the rats. Also, while the aortic blood flow was occluded, NO currents were decreased with exponential pattern with $12.84{\pm}2.15$ seconds of time constant and $7.70{\pm}1.07$ seconds of half-life. To summarize, this study suggested that blood flow-dependent NO concentration and half-life of nitric oxide were about $1.3{\mu}M$ and 7.7 seconds, respectively, in the aorta of anesthetized rats. The nitric oxide-selective electrode system is useful for the direct and continuous measurement of NO in vivo state.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.165-171
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• 2011

A Consider the dead man's switch installed in each and every locomotive cab, which support operational safety on railways around the world. The concept is very simple - every 150 to 180 seconds an illuminated push-button demands to be acknowledged so as to know that the Train Driver is alive and active. In the absence of a response over a period of minutes, the vigilance control will automatically apply the train brakes and bring the train to a stand. If we multiply the resetting of the vigilance control 60 times per hour by a 10-hour shift it equals 600 presses of the button during the shift that a Train Driver must pay attention to and acknowledge. This adds a fair bit of pressure on the train driver's job, particularly when he/she is driving through stations, with passengers moving about on platforms in an environment of complex signaling arrangements - all the while looking out for restricting signals. From this perspective, the Vigilance System's demand to be acknowledged every 150/180 seconds is disturbing and can unnecessarily take a driver's attention away from what is happening outside the confines of the cab. A much more dramatic situation can happen when a train driver is driving hour after hour at night when, by Mother's Nature request - people need to sleep. Experience and research shows that the the dead man's switch can be pressed by train driver in a state of deep relaxation and 'micro-sleep'. The vigilance control system which is applied to reduce the drive load considering bio-response multiple unit train is proposed.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.483-489
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• 2020

Background: Korean Red Ginseng (KRG) has been known to possess many ginsenosides. These ginsenosides are used for curing cardiovascular problems. The present study show the protective potential of KRG against doxorubicin (DOX)-induced myocardial dysfunction, by assessing electrocardiographic, hemodynamic, and biochemical parameters and histopathological findings. Methods: Animals were fed a standard chow and adjusted to their environment for 3 days before the experiments. Next, the rats were equally divided into five groups (n = 9, each group). The animals were administered with KRG (250 and 500 mg/kg) for 10 days and injected with DOX (20 mg/kg, subcutaneously, twice at a 24-h interval) on the 8th and 9th day. Electrocardiography and echocardiography were performed to study hemodynamics. Plasma levels of superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were measured. In addition, the dose of troponin I and activity of myeloperoxidase in serum and cardiac tissue were analyzed, and the histopathological findings were evaluated using light microscopy. Results: Administration of KRG at a dose of 250 and 500 mg/kg recovered electrocardiographic changes, ejection fraction, fractional shortening, left ventricular systolic pressure, the maximal rate of change in left ventricle contraction (-dP/dt_max), and left ventricle relaxation (-dP/dt_max). In addition, KRG treatment significantly normalized the oxidative stress markers in plasma, dose dependently. In addition, the values of troponin I and myeloperoxidase were ameliorated by KRG treatment, dose dependently. And, KRG treatment showed better histopathological findings when compared with the DOX control group. Conclusion: These mean that KRG mitigates myocardial damage by modulating the hemodynamics, histopathological abnormality, and oxidative stress related to DOX-induced cardiomyopathy in rats. The results of the present study show protective effects of KRG on cardiac toxicity.

• Journal of Ginseng Research
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• v.39 no.3
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• pp.206-212
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• 2015

Background: Ginseng total saponin (GTS) contains various ginsenosides. These ginsenosides are widely used for treating cardiovascular diseases in Asian communities. The aim of this study was to study the effects of GTS on cardiac injury after global ischemia and reperfusion (I/R) in isolated guinea pig hearts. Methods: Animals were subjected to normothermic ischemia for 60 minutes, followed by 120 minutes of reperfusion. GTS significantly increased aortic flow, coronary flow, and cardiac output. Moreover, GTS significantly increased left ventricular systolic pressure and the maximal rate of contraction ($+dP/dt_{max}$) and relaxation ($-dP/dt_{max}$). In addition, GTS has been shown to ameliorate electrocardiographic changes such as the QRS complex, QT interval, and RR interval. Results: GTS significantly suppressed the biochemical parameters (i.e., lactate dehydrogenase, creatine kinase-MB fraction, and cardiac troponin I levels) and normalized the oxidative stress markers (i.e., malondialdehyde, glutathione, and nitrite). In addition, GTS also markedly inhibits the expression of interleukin-$1{\beta}$ (IL-$1{\beta}$), IL-6, and nuclear factor-${\kappa}B$, and improves the expression of IL-10 in cardiac tissue. Conclusion: These data indicate that GTS mitigates myocardial damage by modulating the biochemical and oxidative stress related to cardiac I/R injury.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.404-414
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• 2015

Taurine is one of the most abundant free ${\beta}$-amino acids in the human body that accounts for 0.1% of the human body weight. It has a sulfonic acid group in place of the more common carboxylic acid group. Mollusks and meat are the major dietary source of taurine, and mother's milks also include high levels of this amino acid. The leukocytes, heart, muscle, retina, kidney, bone, and brain contain more taurine than other organs. Furthermore, taurine can be synthesized in the brain and liver from cysteine. There are no side effects of excessive taurine intake in humans; however, in case of taurine deficiency, retinal abnormalities, reduced plasma taurine concentration, and other abnormalities may occur. Taurine enters the cell via a cell membrane receptor. It is excreted in the urine (approximately 95%) and feces (approximately 5%). Taurine has a number of features and functions, including conjugation with bile acid, reduction of blood cholesterol and triglyceride levels, promotion of neuron cell differentiation and growth, antioxidant effects, maintenance of cell membrane stability, retinal development, energy generation, depressant effects, regulation of calcium level, muscle contraction and relaxation, bone formation, anti-inflammatory effects, anti-cancer and anti-atherogenic effects, and osmotic pressure control. However, the properties, functions, and effects of taurine require further studies in future.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.237-250
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• 1999

In order to investigate the pharmacologic properties of New Wonbang Woohwangchungsimwon Pill(NSCH), effects of Wonbang Woohwangchungsimwon Pill (SCH) and NSCH were compared using various experimental models. In rat aorta, NSCH and SCH made the relaxation of blood vessels in maximum contractile response to phenylephrine (10-6 M) regardless to endothelium containing or denuded rings of the rat aorta. Furthermore, the presence of the inhibitors of NO synthase and guanylate cyclase did not affect significantly the relaxing effects of NSCH and SCH. NSCH and SCH inhibited the vascular contractions induced by acetylcholine, prostaglandin endoperoxide or peroxide in a dose-dependent manner. In conscious spontaneously hypertensive rats (SHRs), NSCH and SCH decreased significantly heart rate. These, at high doses, had a negative inotropic effects that was a decrease of left ventricular developed pressure and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In guinea-pig papillary muscle, these had no effects on parameters of action potential such as action potential amplitude (APA), $V_{max}$ and resting membrane potential (RMP) at low doses, whereas inhibitory the cardiac contractility at high doses. Furthermore, these had a significant inhibitory effects on palpitation of the heart in normotensive rats and SHRs. These had a significant inhibitory effects on palpitation of the heart in normotensive rats and SHRs. These results suggest that NSCH and SCH have weak cardiovascular effects, and that there is no significant differences between cardiovascular effects of two preparations.

• Research in Community and Public Health Nursing
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• v.15 no.3
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• pp.353-364
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• 2004

Purpose: The purpose of this study was to investigate the types and frequencies of nursing intervention of home health care in Public Health Centers and its effects. Method: The data collection period for this study lasted from March 1 to December 31, 2003. The clients were sampled by a stratified randomized method among those who had been cared for at least 3 months. The data was analyzed by SPSS for description. ANOVA, paired t test, etc. Result: The types and frequencies of nursing intervention in major chronic health problems were significantly different. The main types of nursing intervention in hypertension and DM patients included education on disease management, regular exercise, stress management, diets, etc. CVA patients were intervened in pain control (ice or hot pack, massage), position changes, and ROM exercise. Cancer patients received imaginary or relaxation therapy, pain control (ice or hot pack, massage), hospice, etc. After the intervention, the drug compliance of hypertension (8.2 days per month) and DM patients (6.2 days per month) improved. Blood sugar levels (FBS 7.6, post partum 2hrs $21.4(mg/d{\ell})$ and blood pressure(systolic 9.8, diastolic 4.3 mmHg) lowered significantly. All aspects of QOL also improved (total 3.68). Conclusion: The types and frequencies of nursing intervention were determined by characteristics of the health problems, and home health care nursing intervention in Public Health Centers was effective to the elderly of the community in many aspects.

• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.45-53
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• 2016

A precast panel wall system resists against the horizontal earth pressure by increasing the shear strength of ground by reinforcement connected to the panel. The application of precast panel wall system is growing to lately minimize the earth work and environmental damage caused by large cut slope and to use the limited land effectively. The ground adhered panel wall system is the construction method that has the panel engraved with natural rock shape to improve the landscape. This system is developed to complete Top-Down method, and it is possible to have vertical cut, and to adhere to in-situ ground, improve construction ability by minimizing the ground relaxation and exclusion the trench and backfill process. In this study the field tests were performed to verify the construction ability about the vertical cut and complete Top-Down process and the construction behavior of ground adhered panel wall system was analyzed by large scale loading test and measurement results during loading test.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.918-929
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• 2008

This study investigated the effects of inverted position on EEG and heart rate variability before and after Bang song gong. BSG is a training method using in qi-gong and meditation to give a convergence of consciousness on body segments in order and take a silent speech of 'song'. The subjects were the 14 university students(n=7 per group) who had not experienced any medical problem and had not practiced BSG. They took a practice of the two way of BSG training program for 30 minutes every other day for two weeks. During practicing BSG, A group took sitting position and lean sitting position by turns, B group took inverted and lean sitting position in the same way. Statistical analysis conducted by two-way ANOVA($2groups^{\ast}2periods$) with p<0.05 for average difference of EEG and HR according to position change in each group before and after BSG. In A group, EEG and HR were changeless irrespective of the change of position and BSG. On the other hand, in B group, significant changes were observed in EEG(p<0.05). ${\alpha}$ wave of inverted position were on the increase, ${\beta}$ and ${\delta}$ wave of inverted position showed smaller power after two weeks training. In the variation of HR, there were smaller variation according to the position change after BSG compared to before BSG(p<0.05). The results suggested that an inverted position may make the depth of meditation deeper, and is likely to be effective for decreasing tension of brain and the sleepiness during qi-gong training. In addition to, an inverted position seemed to promote control of blood pressure of brain. So the application of an inverted position to 'BSG' will be very helpful to achieve deeper relaxation and to obtain the desired effect from qi-gong training.

• Korea-Australia Rheology Journal
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• v.19 no.4
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• pp.191-199
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• 2007

Precision injection molding process is of great importance since precision optical products such as CD, DVD and various lens are manufactured by those process. In such products, birefringence affects the optical performance while residual stress that determines the geometric precision level. Therefore, it is needed to study residual stress and birefringence that affect deformation and optical quality, respectively in precision optical product. In the present study, we tried to predict residual stress, final shrinkage and birefringence in injection molded parts in a systematic way, and compared numerical results with the corresponding experimental data. Residual stress and birefringence can be divided into two parts, namely flow induced and thermally induced portions. Flow induced birefringence is dominant during the flow, whereas thermally induced stress is much higher than flow induced one when amorphous polymer undergoes rapid cooling across the glass transition region. A numerical system that is able to predict birefringence, residual stress and final shrinkage in injection molding process has been developed using hybrid finite element-difference method for a general three dimensional thin part geometry. The present modeling attempts to integrate the analysis of the entire process consistently by assuming polymeric materials as nonlinear viscoelastic fluids above a no-flow temperature and as linear viscoelastic solids below the no-flow temperature, while calculating residual stress, shrinkage and birefringence accordingly. Thus, for flow induced ones, the Leonov model and stress-optical law are adopted, while the linear viscoelastic model, photoviscoelastic model and free volume theory taking into account the density relaxation phenomena are employed to predict thermally induced ones. Special cares are taken of the modeling of the lateral boundary condition which can consider product geometry, histories of pressure and residual stress. Deformations at and after ejection have been considered using thin shell viscoelastic finite element method. There were good correspondences between numerical results and experimental data if final shrinkage, residual stress and birefringence were compared.